1. Chapter 3 Cell Structure
Cells are the basic building blocks for all _________…it is important to understand their structures and functions
life

2. Chapter 3
Section 1 Looking at Cells
Objectives
Describe how scientists measure the length of objects.
Relate magnification and resolution in the use of microscopes.
Analyze how light microscopes function.
Compare light microscopes with electron microscopes.
Describe the scanning tunneling microscope.

3. New Vocabulary Light microscope Electron microscope Magnification
Resolution
Scanning Tunneling Microscope

4. microscope Leeuwenhoek animalcules
Most cells are too small to be seen with the naked eye
Scientists were not aware of cells until they invented the __________________
Anton van _____________________ was the first person to view single-celled organisms
He viewed pond water with a microscope and observed many living creatures that he called _________________
microscope
Leeuwenhoek
animalcules

5. 1665
In ________, an English scientist named Robert _________ observed a thin piece of _________ using a microscope
He saw that the cork contained tiny “rooms” that reminded him of the rooms that monks lived in called ___________
You can also think of a ________ cell
Hooke
cork
cells
jail

6. metric International System SI decimal ten Chapter 3
Section 1 Looking at Cells
Cell measurements taken by scientists are expressed in ____________ units.
The official name of the metric system is the _________________ _________________ of Measurement…abbreviated _____
SI is a ________________ system, so all relationships between SI units are based on powers of __________
metric
International
System SI
decimal
ten

7. meter Time kg kelvin A Amount of substance Luminous intensity
There are seven SI base units…
measurement
unit
symbol
Length m
second s
Mass
kilogram
Temperature K
mole
mol
Electric current
ampere
candela cd
meter
Time kg
kelvin
Amount of substance A
Luminous intensity

8. prefix Nano- Chapter 3 Section 1 Looking at Cells
Most SI base units have a ____________ that indicates the relationship of that unit to a base unit
What prefix on the chart indicates the smallest size?
Nano-

9. Chapter 3 Section 1 Looking at Cells Power 103 100 10-2 10-3 10-6 10-9
Let’s place the appropriate power next to each prefix
Power
103
100
10-2
10-3
10-6
10-9

10. Chapter 3 What prefix is usually used for cell sizes? Micro = µ
Section 1 Looking at Cells
What prefix is usually used for cell sizes?
Micro = µ

11. Chapter 3
Section 1 Looking at Cells
When looking at a cell with a microscope, it is necessary to have good…
____________________
the quality of making an image appear _____________ than its actual size
___________________
is a measure of the ___________ of an image
Magnification
larger
Resolution
clarity

12. There are three main types of microscopes…
Light
Electron
Tunneling

13. light
Light microscopes use ___________ to magnify an image
Simple light microscopes use ______ lens
Compound light microscopes use ______ lenses 1 2

14. An image produced by a microscope is called a _______________
They are labeled with the…
Specimen
Type of microscope
magnification
micrograph

15. Chapter 3
Section 1 Looking at Cells
large
Light waves are too _______ to clearly magnify objects smaller than a few __________________
nanometers

16. smaller
Electron beams are _____________ than light waves so electron microscopes can magnify smaller objects with better _____________________
resolution

17. vacuum gas live Chapter 3
Section 1 Looking at Cells
The electron beam and specimen must be in a _______________ so that the electron beam will not bounce off of _________ molecules.
This prevents ________ organisms from being viewed with an electron microscope
vacuum
gas
live

18. Transmission metal Chapter 3 ____________________ Electron Microscope
Section 1 Looking at Cells
Transmission
____________________ Electron Microscope
An electron beam is directed at a very thin slice of a specimen stained with ___________ ions. Some structures become more heavily stained than others.
metal

19. absorb
The heavily stained parts _____________ electrons, those that are lightly stained allow electrons to ___________ through.
The electrons that pass through strike a fluorescent screen, forming an image that allows you to see _______________ structures
pass
Internal

20. Scanning coated Chapter 3 _______________________ Electron Microscope
Section 1 Looking at Cells
Scanning
_______________________ Electron Microscope
An electron beam is focused on a specimen ________ with a very thin layer of metal.
coated

21. three-dimensional surface
The electrons that bounce off the specimen form an image on a fluorescent screen.
The image shows __________________ details of the ______________ of a specimen.
three-dimensional
surface

22. voltage “tunnel” computer three-dimensional live atoms Chapter 3
Section 1 Looking at Cells
Scanning Tunneling Microscope
A needle-like probe measures differences in ______________ caused by electrons that leak, or ____________, from the surface of the object being viewed.
A ________________ tracks the movement of the probe and produces a __________________ image of the surface of the specimen.
STMs allow _______________ specimens and objects as small as ______________ to be viewed!
voltage
“tunnel”
computer
three-dimensional
live
atoms

23. STM image of an iron atoms

24. Question #1
What metric prefix is used most often while measuring cells?
Micro- (µ)

25. Magnification – enlarging an object Resolution - clarity
Question #2
What is the difference between magnification and resolution?
Magnification – enlarging an object
Resolution - clarity

26. Simple – one lens Compound – two lenses Question #3
What is the difference between a simple and compound microscope?
Simple – one lens
Compound – two lenses

27. Transmission electron microscope
Question #4
Which type of electron microscope allows you to see internal cell structures?
Transmission electron microscope

28. Scanning tunneling microscope
Question #5
Which type of microscope allows you to observe live specimens and objects as small as an atom?
Scanning tunneling microscope